Prevalence of malocclusions in a sample of 4-5-year-old Bulgarian children
General
Table 1. Prevalence of spacing, no spacing and crowding in primary dentition. |
Gender |
Type 1 |
Type 2 |
Type 3 |
Total |
Girls |
172( 74.8 %) |
50( 21.7 %) |
8( 3.5 %) |
230( 100 %) |
Boys |
196( 81.3 %) |
26( 10.8 %) |
19( 7.9 %) |
241( 100 %) |
Total |
368( 78.2 %) |
76( 16.1 %) |
27( 5.7 %) |
471( 100 %) |
Table 2. Prevalence of normal, increased and decreased overjet in 4- and 5-year old children. |
Age |
Overjet 0-3mm |
Overjet 3-6 mm |
Overjet > 6 mm |
Overjet < 0 mm |
Total |
4 years |
138( 87.9 %) |
10( 6.4 %) |
2( 1.3 %) |
7( 4.5 %) |
157( 100 %) |
5 years |
265( 84.4 %) |
31( 9.9 %) |
2( 0.6 %) |
16( 5.1 %) |
314( 100 %) |
Total |
403( 85.6 %) |
41( 8.7 %) |
4( 0.8 %) |
23( 4.9 %) |
471( 100 %) |
Table 3. Primary canine sagittal relationships. |
Age
4 years
5 years
Total
Class I Class II Class III Right Left Right Left Right Left
92( 58.6 %)
181( 57.6 %)
273( 58.0 %)
102( 65.0 %)
187( 59.6 %)
289( 61.4 %)
45( 28.7 %)
103( 32.8 %)
148( 31.4 %)
37( 23.6 %)
100( 31.8 %)
137( 29.1 %)
20( 12.7 %)
30( 9.6 %)
50( 10.6 %)
18( 11.5 %)
27( 8.6 %)
45( 9.6 %)
Total
157( 100 %)
314( 100 %)
471( 100 %)
Table 4. Second molar sagittal relationships.
Age
4 years
5 years
Total
Flush terminal Mesial step Distal step Right Left Right Left Right Left
117( 74.5 %)
213( 67.8 %)
330( 70.1 %)
119( 75.8 %)
222( 70.7 %)
341( 72.4 %)
21( 13.4 %)
52( 16.6 %)
73( 15.5 %)
19( 12.1 %)
43( 13.7 %)
62( 13.2 %)
19( 12.1 %)
51( 16.2 %)
70( 14.9 %)
19( 12.1 %)
47( 15.0 %)
66( 14.0 %)
Total
157( 100 %)
314( 100 %)
471( 100 %) and a mesiocclusion in 10 %. A distribution of a flush terminal molar relationship in percentages is 70.1 % on the right side and 72.4 % on the left side of the examined subjects. The mesial step was assessed as 15.5 % on the right side and 13.2 % on the left side. And the distal step was assessed as 14.9 % on the right side and respectively 14 % on the left side. There are no statistically significant differences between gender in the primary canine relationships and the second primary molar relationships. But we found a statistically significant increase in Class II canine relationships between the age groups( χ2 = 3.479, p = 0.062). A normal overbite was found in 30.1 % of the sample and an anterior edge-to-edge bite existed in 27.2 % of all the children, with no significant differences between gender and age in the subgroups. A moderate anterior open bite(< 3mm) and a severe anterior open bite(> 3mm) were registered respectively in 6.8 % and 0.4 %. A posterior open bite was documented in 1.3 % of all children. A deep overbite was found in 127 children( 27.0 %) and a deep overbite with gingival contact in 40 children( 8.5 %). Statistically significant was the fact that boys showed more deep bites with gingival contact( χ2 = 3.347, p = 0.067) and also the difference between the age groups was statistically significant( χ2 = 3.497, p = 0.061)- an increase of the frequency was observed with the increasing of the age. A unilateral posterior cross-bite was observed in 3.2 % of the sample and a bilateral posterior cross-bite in 1.5 %. An edge-to-edge bite in the posterior region was found in 9 cases with a statistically significant difference in age comparison( χ2 = 8.156, p = 0.004), the 4-year-olds showed more edge-to-edge bites than the 5-year-olds. In this sample, a scissor bite was not registered. The total percentage of mandible lateral deviation was 2.5 %. A mandible deviation to the right side was found in two cases and 10 cases to the left side. The percentage prevalence of malocclusions in primary dentition is shown in Table 5.
70 Stoma Edu J. 2017; 4( 1): 68-73. http:// www. stomaeduj. com